Strip process for high aspect ratio structure

Abstract

Processes for removing a mask layer (e.g., doped amorphous carbon mask layer) from a substrate with high aspect ratio structures are provided. In one example implementation, a process can include depositing a polymer layer on at least a portion of a top end of a high aspect ratio structure on a substrate. The process can further include removing at least a portion of the polymer layer and the doped amorphous carbon film form the substrate using a plasma strip process. In example embodiments, depositing a polymer layer can include plugging one or more high aspect ratio structures with the polymer layer. In example embodiments, depositing a polymer layer can include forming a polymer layer on a sidewall of one or more high aspect ratio structures.

What is claimed is: 
     
       1. A process for removing at least a portion of a doped amorphous carbon film from a substrate having a high aspect ratio structure, the process comprising:
 depositing a polymer layer on a top end of the high aspect ratio structure on the substrate; and 
 removing at least a portion of the polymer layer and the doped amorphous carbon film from the substrate using a plasma strip process; 
 wherein depositing the polymer layer comprises plugging the top end of the high aspect ratio structure with the polymer layer such that the polymer layer extends partially into the high aspect structure so that exposure of an underneath layer associated with the high aspect ratio structure is reduced during the plasma strip process; 
 wherein the high aspect ratio structure comprises a trench formed from alternating layers of oxide and nitride, wherein the polymer layer extends only partially into the trench of the high aspect ratio structure. 
 
     
     
       2. The process of  claim 1 , wherein depositing the polymer layer comprises forming the polymer layer on a sidewall of the high aspect ratio structure. 
     
     
       3. The process of  claim 1 , wherein the polymer layer is formed using polymer deposition with one or more of CHF 3 , H 2 , N 2 , Ar or their combination. 
     
     
       4. The process of  claim 1 , wherein the polymer layer is formed using a gas C x H y F z  combined with any H 2  or any C x1 H y1 , where x, y, z, x1, and y1 are integers. 
     
     
       5. The process of  claim 1 , wherein the polymer layer is formed at a pressure in the range of about 10 mTorr to about 5 Torr. 
     
     
       6. The process of  claim 1 , wherein depositing a polymer layer is performed in an etch chamber and removing at least a portion of a polymer layer and the doped amorphous carbon film is performed in a strip chamber that is separate from the plasma chamber. 
     
     
       7. The process of  claim 1 , wherein depositing the polymer layer and removing at least the portion of the polymer layer and the doped amorphous carbon film are performed in a single chamber. 
     
     
       8. The process  claim 1 , wherein depositing the polymer layer and removing at least the portion of the polymer layer and the doped amorphous carbon film are repeated until the doped amorphous carbon film is removed from the substrate. 
     
     
       9. The process of  claim 1 , wherein the plasma strip process uses a plasma formed using a mixture of an oxygen containing gas, a halogen containing gas, and a reducing gas that includes hydrogen. 
     
     
       10. The process of  claim 9 , wherein a ratio of the reducing gas to the halogen containing gas is in the range of about 0.001:1 to about 3:1. 
     
     
       11. The process of  claim 1 , wherein the doped amorphous carbon film is a boron doped amorphous carbon film.